The initially mentioned joint parts are intended for constant velocity universal ball joints which are produced by the applicant under the designation of TBJ (Twin Ball Joints) and are described in DE 10 2004 018 721.5. In a way known in itself, these constant velocity universal ball joints also comprise an outer joint part with first ball tracks positioned in an inner guiding face for a ball cage; an inner joint part with second ball tracks formed on an outer guiding face for the ball cage; balls inserted into pairs of first and second ball tracks; as well as a ball cage which holds the balls in a common plane. The ball cage is provided with individual windows for accommodating the balls.
In the TBJ joints mentioned here, both the first ball tracks in the outer joint part and the second ball tracks in the inner joint part, in turn, are arranged in pairs, with pairs of said further type being designed in such a way that they comprise central track planes positioned in parallel planes. In this way it is possible for two balls, which are guided in such pairs and whose circumferential distance from one another along the entire track length does not change, to be held in an individual common window, i.e. the number of cage windows relative to the ball tracks can be halved.